Diaphragm for transmitters and receivers



Sept. 28 1926. 1,601,656

A. S. THAYER DIAPHRAGMNFO'R TRANSMITTERS AND RECEIVERS Fi Ap il 13,1925' Q/fff Patented Sept. 28, 1926.

UNITED STATES ARTHUR S.,THAYER, 01? LAKEWOOD, OHIO.

DIAPHRAGM FOR TRANSMITTERS AND RECEIVERS.

Application filed April 13, 1925.

object to improve the efficiency of such diaphragms, particularly in thematter of preventing such distortions in the said diaphragms as willresult in distortions in the sounds produced through the operationthereof. A further object of'the invention is to provide a diaphragm ofthis character which will prevent vibrations of the central portionthereof from reaching the peripheral clamping portion of the same,thereby eliminating rattling noises. The advantages referred tohereinbefore, as well as others, to be discussed hereinafter, will berealized in and through the construction and arrange ment of parts shownin the drawings, wherein Fig. 1 represents a central vertical sectionalview through a receiver such as is used with a radioloud-speaker, thesaid receiver being provided with my diaphragm; Fig. 2 a plan view ofthe diaphragm; Fig. 3 a sectional view of the dia hragm corresponding tothe line 33 of ig. 2; Fig. 4 a similar view showing the manner in whichthe diaphragm responds to sound waves when used with transmitters and toelectrical impulses of the pole pieces when used with receivers; andFig. 5 a sectional view corresponding to the line 5-5 of Fig. 2.

Describing the various arts by reference characters, 1 denotes the baseof a support, the one shown herein being of the typeemployed with theloudspeakers of radlo sets. The base is in the form of a downwardly andoutwardly flaring casing having a cylindrical top provided with aninternal thread 1 for the reception of a receptacle 2 containing thecoils 3 and pole pieces 4. 5 denotes a cover for the base 1, having acentral opening into which is threaded the,

neck 6 of a horn or other sound-amplifying device. A represents thediaphragm generally, the marginal portion 7 of the diaphragm beingclamped between the marginal flange 5 on said cover 5 and the top of thebase 1, screws 8 being shown as extending throu h apertures 9 in suchmarginal portion of t e giaphragm and securing the cover to the ase.

Within and adjacent to the clamping flange 5",

the diaphragm is provided with Serial No. 22,718.

an upwardly extending annular V-sha ed rib 10 which is pressed therefromand within and enclosed by the rib 10 is an upwardly projecting V-shapedrib 11, the last mentioned rib being polygonal in outline and shownherein as having four sides, although the particular number of sides maybe varied in accordance with the uses to which the diaphragm is applied,it being preferred to use more sides with a transmitter diaphragm thanwith a receiver diaphragm.

Within the rib 11, the diaphragm is provided with an upwardly projectingrib 12, which is also polygonal and has lts sides parallel with thesides of the ribs 11. Extending outwardly from each outer corner of therib 12 toward and preferably as far as the corresponding inner corner ofthe rib 11 is a rib 13, each of the ribs 13 gradually diminishing inwidth and depth from the rib 12 toward the rib 11, with like variationin the width and depth of the grooves formed therebeneath.

In the construction of the diaphragm just described, I employ highsilicon steel, as this steel has no residual magnetism and is thereforeimmediately reponsive to changes in polarity; and I prefer to use metalof approximately 36 gauge for my diaphragms.

A diaphragm constructed as described is provided with a relatively largecentral polygonal space A, said space being defined by the rib 12 andthe groove therebeneath, with a space surrounding such central space andincluded between the ribs 11 and 12 and the grooves therebeneath, thesurrounding space in turn consisting of a number of polygonal spaces Adefined by the ribs 11, 12, and ribs 13. and by the grooves beneath saidribs.

In operation, when the diaphragm is subjected to an impulse (either anelectrical impulse due to the pole pieces 4 or an impulse due to theimpact of a sound wave thereagainst), the extended central portion Amoves bodily inwardly, such central portion remaining in the same plane,during such movement, as shown in Fig. 4, this action being due to theprovision of the rib 12 and the groove therebeneath, which allows thecentral portion to flex bodily downwardly, drawing at its periphery uponthe surplus metal in the rib and rocking at such periphery upon suchrib. The metal surrounding such central portion and within the rib 11flexes downwardly from such rib toward the rib 12. Each segment A,defined by and between the ribs 11, 12 and 13, moves as a plane, rockingabout the central portion of the groove 11 as a pivot or fulcrum, thisaction being permitted by the ability of each segment A to draw upon thesurplus metal in the ribs 11, 12 and 13.

Ordinarily the metal in the part A of the diaphragm between the ribs orbeads 10 and 11 will not be deflected, the rib 10 serving to dissipateany vibrations of the diaphragm which may reach it and prevent suchvibrations from reaching the clamping seat. thereby preventing anyrattling noises in the receiver or transmitter.

\Vith the parts constructed. arranged. and operating as described, theonly vibrations which will beproduced in the enlarged central section ofthe diaphragm are the bodily vibrations of such central portion towardand from the actuating means, while the vibrations in the parts A willbe the vibrations of said parts as planes hinged or pivoted to the ribor bead 11; and no cross vibrations will be set up in the parts A and Awhich cross vibrations would result in distortion in the sounds receivedor transmitted by the diaphragm.

As pointed out hereinbefore, it is desirable to have the central part Apolygonal, rather than circular, as it is believed that the use of acircular central portion, with a circular surrounding rib, would resultin too great flexibility of such central portion.

The ribs 13 serve to stiffen the rib 12 and to prevent unnecessarilygreat movement or deflection of the central part A. Furthermore, theseribs constitute fulcra for the short sides or corners of the segments Awhich fulcra can open up under deflection of the parts A When mydiaphragm is to be used as a transmitter, more ribs 13 will be employedthan when it is used as a receiving diaphragm.

A diaphragm constructed from the material and in the manner shown anddescribed herein has been found to be of marked efficiency when usedwith the receiver of a radio set, the diaphragm giving perfectreproduction of whatever may be transmitted from a radio microphone andshowing no natural frequency period of its own.

Having thus described my invention, what I claim is 1. A metal diaphragmfor receivers or transmitters, the said dia hragm having a rib pressedtherefrom an enclosing an extended fiat central portion, said diaphragmalso having a second rib pressed therefrom and surrounding and spacedfrom the first rib, there being radial ribs extending from the first ribtoward, but not across. the second rib, the said radial ribs diminishinguniformly in depth and width from the first rib toward the second rib.the said dia phragm also having a rib pressed therefrom and surroundingand spaced from the second rib and the diaphragm also having a marginalclamping portion located outside the last-mentioned rib.

2. A metal diaphragm for receivers or transmitters, the said diaphragmhaving pressed therefrom a rib Vshaped in section and enclosing anextended flat central portion, the diaphragm also having pressedtherefrom a rib V-shaped in section and surrounding and' spaced from thefirst rib, there being radial ribs extending from the first rib towardthe second rib, the said radial ribs also being of V-sliaped incross-section and diminishing uniformly in depth and width from thefirst rib toward the second r b, the diaphragm also having a rib pressedtherefrom and surrounding the second rib and the diaphragm having amarginal clamping portion outside the last-mentioned rib.

3. A metal diaphragm for receivers or transmitters, the said diaphragmhaving a polygonal rib V-shaped in section pressed therefrom andenclosing an extended fiat central portion, the said diaphragm alsohaving a polygonal rib V.-shaped in section pressed therefrom andsurrounding and spaced from the first-mentioned rib, there being radialribs extending from the first rib toward the second rib, the said radialribs also being of V-shape in cross-section and diminishing uniformly indepth and width from the inner rib toward the outer rib and saiddiaphragm havin a marginal clamping portion outside the said ribs.

4. A metal diaphragm for receivers or transmitters, the said diaphragmhaving a polygonal rib V-shaped in section pressed therefrom andenclosing an extended flat central portion, the said diaphragm alsohaving a polygonal rib V-shaped in section pressed therefrom andsurrounding and spaced from the first-mentioned rib, there being radialribs extending from the first rib toward the second rib, the said radialribs also being of V-shape in crosssection and diminishing uniformly indepth and width from the inner rib toward the outer rib, the diaphragmalso having a rib pressed therefrom and surrounding the second rib andsaid diaphragm having a marginal clamping portion outside the said ribs.

In testimony whereof, I hereunto afiix my signature.

ARTHUR S. THAYER.

